Growth and structure of carbon nanotubes produced by thermal chemical vapor deposition

Vertically aligned carbon nanotubes are synthesized with high density on a large area of cobalt-deposited silicon oxide substrate by thermal chemical vapor deposition of acetylene at 950 degreesC. The diameters of the carbon nanotubes are distributed in the range 80-120 nm and the length is about 20 mum. The carbon nanotubes have a bamboo-like structure in which the curvat ure of the compartment is oriented to the tip. The tips are closed and free of encapsulated catalytic particles. The emission current density is 1.1 m A/cm(2) at an applied field of about 4.5 V/mum, following the Fowler-Nordhe im behavior. (C) 2001 Published by Elsevier Science Ltd.